Sanofi has signed a licensing agreement worth up to $1.04 billion with South Korea–based biotech Adel, marking a major Sanofi Alzheimer’s deal aimed at strengthening its neurology pipeline. The agreement gives the French drugmaker global rights to a first-in-class investigational Alzheimer’s antibody.
Sanofi Alzheimer’s Deal Gives Sanofi Global Rights to Phase One Alzheimer’s Antibody
Sanofi will pay Adel $80 million upfront for exclusive worldwide rights to ADEL-Y01, an investigational antibody therapy aimed at treating Alzheimer’s disease, the companies said in a statement released after markets closed Monday.
The agreement includes potential milestone payments that could bring the total deal value to about $1.04 billion, plus tiered royalties on future sales. Sanofi also gains access to related backup compounds tied to the program.
Adel is a clinical-stage biotech based in Seoul. Sanofi said the deal strengthens its neurology pipeline as it seeks new approaches for neurodegenerative diseases with high unmet medical need.
“This agreement reflects our focus on innovative science that can address the root causes of complex neurological conditions,” Sanofi said in the release.
Experimental Drug Targets Toxic Tau Protein in the Brain
ADEL-Y01, the centerpiece of the Sanofi Alzheimer’s deal, is a humanized monoclonal antibody designed to selectively target tau protein acetylated at lysine-280 (acK280). Abnormal tau accumulation is a defining feature of Alzheimer’s disease and other neurodegenerative disorders.
According to the companies, the antibody is engineered to block the aggregation and spread of toxic tau while preserving the normal function of healthy tau that supports neuron structure.
The therapy emerged from Adel’s proprietary platform focused on tau modification. In 2020, Adel began co-developing the asset with South Korea-based pharmaceutical company Oscotec.
ADEL-Y01 is currently undergoing a global phase one clinical trial to evaluate safety and early biological activity. Under the Sanofi Alzheimer’s deal, Sanofi will assume responsibility for further clinical development and eventual commercialization.
“Adel’s innovative approach to targeting tau acetylation offers a promising and differentiated mechanism for addressing the underlying causes of Alzheimer’s disease,” said Erik Wallstroem, Sanofi’s global head of multiple sclerosis, neurology and gene therapy development.
“We look forward to advancing ADEL-Y01 through clinical development to provide new hope for patients living with this devastating condition,” Wallstroem said.
Pact Caps Active Day as Sanofi Faces Setbacks Elsewhere
The Alzheimer’s agreement marked Sanofi’s second biotech deal announced Monday. Earlier in the day, the company said it expanded its partnership with Dren Bio to develop a potential next-generation B-cell depleting therapy for autoimmune diseases.
In recent days, Sanofi also entered a new collaboration with the U.S.-based InduPro Therapeutics, another deal focused on autoimmune conditions, highlighting an active period for business development.
The flurry of partnerships comes as Sanofi faces challenges in other parts of its pipeline. On Monday, the company said the U.S. Food and Drug Administration delayed a decision on Tolebrutinib, its investigational BTK inhibitor for non-relapsing secondary progressive multiple sclerosis. A regulatory decision is now expected by the end of March 2026.
Sanofi also disclosed that Tolebrutinib failed to meet its primary endpoint in a phase three study for primary progressive multiple sclerosis. The company said it will not seek approval for the drug in that indication.
Despite the setback, Sanofi said it remains committed to expanding its neurology portfolio through internal research and external partnerships.
